ICL's October meeting on 10/6 featured a timely presentation from Alexander Tardy of NOAA, who spoke about the expected effects on Southern California and the canyons from this year's large "El Nino".

This presentation and guests were arranged by ICL's Emergency Disaster Preparedness committee headed by Joanne Hubble. Our thanks to her for a great job. And also thanks to Mr. Tardy and the other guests listed below who attended to answer questions.

We had an overflow crowd and some people couldn't get in. Alex Tardy's slides are at the bottom of this post, and a video recording of his presentation is just below.Our thanks to Dion Sorrell of Modjeska Canyon for making this video available to us.(If you want to view it full-screen, click the "box" icon at the lower right of the video.)

The brief takeaway from the presentation:

This summer’s rain and high humidity so far has been mostly from two warm-water ocean “blobs” off the pacific northwest, and notEl Niño (also termed "ENSO"). ENSO is warm water event that happens much farther south in the equatorial regions off the west coast. See the slides below.

El Niños affect our local weather mainly by redirecting the upper atmosphere's westerly jet stream, pulling a trough to the south and so redirecting the usual winter storm track down from the pacific northwest and Canada into California.

The effects of an El Niño vary widely, but this year's El Niño is big, scoring at 2.5 on a scale of 3.0. So it is unlikely to be a "dud.” If it stays at 2.5, it will be the strongest on record for sea surface temperatures in the equatorial pacific.

El Niño usually results in a cooler and longer rainy season, possibly extending through May. This one will produce more storms and/or more intense storms. But whether any particular storm will be unusually intense is not known. And the rain rates this year also may be enhanced by our unusually warm coastal waters.

But The Most Important Of All...Because of these uncertainties, if you live in the canyons you must be prepared to deal with extensive rainfall this winter and spring, however and whenever it arrives.